Well tools



2 Sheets-Sheet 2 ATTURNEY Dec. 13, 1955 L. M. wlLHlT l-:TAL

WELL TOOLS Filed Sept. 8, 1952 United States Patent() WELL rooLs Lowell M. Wilhoit, Harry B. Schramm, and Herbert C. Otis, Dallas, Tex.

Application September 8, 1952, Serial No. 308,409

16 Claims. (Cl. 166- 224) This invention relates to well tools and more particularly to a by-pass tool having a removable choke therein.

One object of the invention is to provide a by-pass tool for connection in the ow string of wells for selectively permitting the commingling of fluid within the iiow string with tluid from without the ow string.

An important object is to provide a housing connectable in a flow string having Vlateral openings and a bore which are selectively closable by a removable choke, whereby ow of uids in the iiowl string may be selectively chosen to be either uid from exteriorly of the ow string and housing or uid from within the flow string or both.

A particularly important object of the invention is to provide a by-pass tool of the character described, having a lateral opening from exteriorly to interiorly thereof and a landing nipple for a removable choke controlling said lateral opening, said by-pass tool having an amplified flow passage past said lateral opening for substantially unrestricted flow of fluids therepast, whereby said by-pass tool is adapted for use in formation-fracturing or acidizing treatment of wells, or the like.

Still another object of the invention is to provide a housing connectable in a ow string and having a landing nipple with a lateral ow port and closable by a removable choke for selectively flowing uid upwardly through said ow string so that either uid within the flow string or duid from without the ow string may be separately owed up said ow string, the choke being provided with a locking means for holding it in place in the landing nipple and with a valve for equalizing the pressures acting on the choke whereby the choke can be easily removed from the landing nipple. Y

A particular object of the invention is to provide a by-pass tool in the form of a housing having an enlarged longitudinal bore and a lateral port and a landing nipple in said housing and spaced Yfrom the wall thereof to provide an annular Iiow passage therebetween, the nipple having a lateral port communicating with the lateral port of the housing by means of a conductor closed oli from the annular ow passage between said housing and nipple.

Another object of the invention is to provide a by-pass tool in the form of a housing having an enlarged longitudinal bore with a landing nipple therein spaced from the wall of said bore to provide a ow passage therebetween and a lateral conductor from exteriorly of the housing to the interior of the nipple, and having a removable choke releasably locked in said nipple with a bore in said choke communicating with the lateral conductor whereby the full bore of the choke may be used to control fluid flow through said lateral conductor.

A further object of the invention is to provide'a bypass tool for connection in a ow string having a removable choke for preventing ow of uid between upper and lower sections of the string and simultaneously permitting flow of uid between upper sections of the flow string and the exterior of the housing.

A still further object of the invention is to provide a 2,726,724 Patented Dec. 13, 1955 2, by-pass tool having a housing connectable in a ilow string closable by a removable choke which prevents the ow of fluid between upper and lower sections of the housing and permits the ow of fluid between the interior and exterior of the housing, the choke being provided with a locking means for holding it in place and with a valve for equalizing the pressures acting on the choke whereby the choke is easily removable.

Additional objects and advantages of the invention will be readily apparent from the reading of the following description of a device constructed in accordance with the invention, and reference to the accompanying drawings thereof, wherein:

Figure l is a vertical, partly sectional view of a prererred embodiment of the by-pass tool showing a choke in position in the landing nipple and with its pressure equalizing valve in closed position,

Figure 2 is a vertical sectional view of the tool shown in Figure l, showing the pressure equalizing valve of the choke in open position,

Figure 3 is a horizontal sectional View taken on the line 3 3 of Figure 1,

Figure 4 is a sectional View taken on the line 4--4 of Figure l,

Figure 5 is a vertical, partly sectional view of the by-pass tool having a choke for preventing ow of fluid between upper and lower sections of the flow string, the pressure equalizing valve of the choke being shown in closed position, and

Figure 6 is a vertical sectional View of the tool shown in Figure 5, showing the pressure equalizing valve of the choke in open position.

Referring now particularly to Figures 1 to 4 of the drawings, the numeral 10 designates a housing shown to be internally threaded at its upper and lower ends, with subs 11 and 12, respectively, which permit the connection of the housing in a ow string of a well. A smaller landing nipple 13 has wings 14 and 15 which abut the housing adjacent the opposed lateral apertures or ports 16 and 17 in the housing. Welds 18 and 19 rigidly secure the wings 14 and 15 to the housing. The landing nipple is also provided with a plurality of spacer lugs 2l) which abut the internal wall of the landing nipple and assist in holding the landing nipple in concentric alignment in the housing. An annular by-pass passage 52 is thus formed between the exterior of the landing nipple and the interior of the housing, whereby uids may flow therethrough upwardly past the landing nipple. The bores of the lower sub 12 and the landing nipple 13 are preferably smaller than the bore of the flow string (not shown) in which the device is connected. The bore of the upper sub 11 is larger than the bore of the landing nipple and lower sub.

The wings 14 and 15 of the landing nipple are provided with lateral bores 21 which communicate with the longitudinal bore 22 of the landing nipple and the lateral ports 16 and 17 of the housing whereby fluids may iiow from the exterior of the housing into the bore of the nipple. A removable choke C is employed to control or prevent such ow of fluids. The choke C includes a mandrel 23 having an annular enlargement or ange 24 intermediate its ends provided with a plurality of inlet ports 25 which communicate with the annular space 26 between the ange 24 and the internal wall o' the nipple and also with the central bore 27 of the choke mandrel.

The lower end of the choke mandrel is threaded to receive a pair of packing nuts 28 which serve to hold in place a lower packing assembly 29, preferably of opposed sets of chevron type sealing rings, disposed about the choke mandrel below the ange 24, the lower annular shoulder 30 of the ange cooperating with the packing nuts to hold the packing assembly on said choke mandrel.

Vabove the ports 21 of the latter.

The lower packing assembly- 29 prevents ow of uid between the choken mandrel andthe landing nipple below the ports 21 of the latter.

The upper end of the choke mandrel is also threaded Vto engageinthe lower -end ofthe bore of a locking expander` mandrel31. -Anupper. packing assembly.` 32, also pret"- erably consisting of opposed sets-of-cheyron type sealing rings, is disposedabout the upper portion of the chokeV Y mandrel and is held in place between a spacer ring 33 and the upper annular shoulder 34 of the flange 24 et` Y while a valve plunger 36 having a seal ring 37 in external annular groovein said valve plunger closes the upper end of the central bore of said mandrel by contact l With a reducedV internal annularV iange 38 in the upper portion of the bore ofY the choke mandrel. The valve plunger is held in closedrposition by a shear pin 39 Which` extends throughthe plunger and throughV the mandrel, and also byl an O-ring`40 on the upper-end of the valve stern 41. TheyO-ring is disposed iny an annular groove 42 at the upper end of the valve stem and rests on the upper annular surface ofa tubular neck member 43 whose lower end is threaded in the locking expanderV mandrel 31 for thepurpose of preventing detritus entering the bore of the neck member.v

The locking expander mandrel 31 is provided with an inclined expanding surface 44 which is engagedby a plurality of dogs 45hung by hooks 46 at their upperends on an internal annular flange 47 formedin the. bore of a dog carrier 4S which is slidably disposed on the tubular neck memberA 43. The dogs 45 are moved to expanded positions to project into an internal annular locking recess groove 49 formed in the upper portion of theV landing nipple when the locking mandrel ismoved upwardly relative to the dog carrier. The dogs, when. in expanded posi tion, engage, beneath, a downwardly facing beveled shoulder 50 at the upper end of the annular locking recess in the landing-nipple and thusprevent upward displacement' of the .choke C from said nipple.

In use, the housing is connected in the flow string ofv a well by means of theupperand lower subs 11 and Y 1,2, The choke may or may not be initially in place.

Assuming that it is not, fluids may ilow throughthe longitudinal bore 51 of the landing nipple and also through the annular by-pass passage-52 betweenthe landing nipple and the housing. Fluids may flow in either direction through the ports 21 of the wings and the ports liand 17 of the housing, wherebythe uid in the ow string and the/uidon the exteriorV thereof may commingle.V

If it is now desired to prevent flow of uid through the ports 16 and 17, the choke C is lowered in the flow string into the housing andthe landing nipple by the use of any suitable running tool which may engage either the, ilange 53 at theV upper end of thedog carrieror the ange 54 at the upper end of the neck member 43 to hold the chokethereby. If the running tool is connected to the dog carrienthe dogs will be inretracted position, since the neck member 43 will be in its lowermost position relative to the dog carrierV with its ange 54 abutting the upper end of the ange 53 of the, dogk carrier. If the running tool is connected to the neck member, the dog carrier and dogs are suspended in'their lowermost expanded position, but are freely slidable upwardly therefrom to rretracted position upon engaging the upper end of the landing nipple whereby the dogs may enter the bore of the nipple. n The choke is lowered until the-dogs 45 are;positioned inthe landing nipple adjacentthe lockingrecess or groove 49,*and the line on which the running .tool is suspended is operated to cause upward movement of the locking mandrel 31 relative to the dogs whereby the latter'are moved outwardly by the inclined surface 44 to project into the locking recess. choke are then in the positions shown in Figure l. Fluid may now ow upwardly onlythrough the annular ow passage 52 between the landing nipple and the housing,

which is obviously substantially longer than any bore which could be provided through the choke. The owof fluid into the longitudinal bore 51 of the landing nipple from the ow string is now-prevented by the choke, the

plug 35 andthe valve 36 sealing the upper and lower ends of the central bore 27 ofthe-chokemandrel, and the packing assemblies 29 and 32 sealing between the landing nipple and the choke mandrel'above and below the lilange 24 of the mandrel. The ow of uid from the exterior of the housing is also stopped by the same sealing means.

If it is desiredto remove: the choke-,fthe upward pressure exerted on Ythe choke by the uidonthe interior and exterior of the housinggand landing-nipple mustb'e relieved 1 orV substantially equalized, since such pressure Vtends to hold the locking mandrel in its, uppermost position.Y Otherwise, even-severe blowsoni the top of the tubular member 43 might not succeedindriving the locking f mandrel down tol freeV the, dogs for movement into re tracted; position; and if-the;dogs werefreed, the choke might be blown'up thetlow stringandbecome hung up therein or damage the ilow string orwell surface connec# tions.

It will be seenvthat the upper end of the valve stem 4l projects above the Upper. end `of theA neck member, so that when a suitable pulling tool isi lowered through the ilow string it will first' strike theupper end ofthe valve stem,

forcing it down; Vthe O'ring.40;being expanded and 'moved out of itsgroove and the 39beingsheared'by thisV blow. The valve plunger 36- will then drop downto the position shown infFigure 2,` the :guide tins below the valve plunger preventing' the, valvepl'unger from becoming lodged improperly or jammed inrthe central bore 27 of the choke mandrel. Fluid may nou/,.ow through the ports 16 and 17 of theannular space 26, v.through the ports 25 upwardly intoV the central bore 27v and then Y upwardly through'thecentral boretsincel the valve 36110 longer seals the upper'end of: the vcentral bore. Y `With the surface controls (not shown) closed,l the pressures below and above the locking mandrel and choke are more ork less equalized after the valve plunger'isfunseated, so'that a sharp blow on the uppe1-^end'of'the neck' member 43 will cause the locking mandrel 31;to move downwardly relative to the dogseuntil the ange 54 on the upper end of the neck member-engagesgthe upper endjof the dog carrier. When-the-pullingftoolgnow engages the flange 53 of the dog carrier. andpulls, ,thedog carrierv upwardly, the dogs 45 are freeinftheir'retracted.positions and the choke canbe liftedgupwardly.-` i

It will now be seenthat'ralbyfpass Vtool hasbeen provided which includesa housing 10;connectable in a ow string and having a landing nippler concentrically Vdisposed thereinanda longitudinal annular bypass ow passage 52 between, said nipple and housing-fthe housing and nipple having connected ports whereby uid'may pass between the longitudinalboreSl of the landingl nipple and the exterior of thehousing.V f Furthermore, it will be seen that an easily-removablechoke-C has been provided.

which has'a locking means for holdinggit in'position in the landing nipple vand means -for closing the passage-V through the bore-ofthe landing nippleso that fluids ilow rupwardly through'theannular'by-passfpassage of the The various elements of the,

ple13, and the locking mandrel"31, andthen'associated parts are identical in structure to the corresponding elcments of the tool illustrated in Figures l to 4, and are therefore identified by the same reference numerals. f

The modified form of the choke has an elongate mandrel 6G threaded at its upper end into the locking mandrel 31 and provided with an upper annular ange 61 on which rests a chevron packing assembly 62 held in place by the spacer ring 63. The packing assembly 62 seals between the choke mandrel and the landing nipple above the ports 21 to prevent ow of fluids therebetween in either direction.

A lower annular ange 64 on the lower portion of the choke mandrel provides an annular downwardly facing shoulder 65, and a second chevron packing assembly 66 is disposed on the lower end of the choke mandrel between the shoulder 65 and a packing nut 67 threaded ou the lower end of the mandrel. The chevron packing assembly 66 seals between the choke mandrel and the sub l2 to prevent flow of fluid therebetween either upwardly or downwardly through the sub.

A cap 68 is also threaded on the lower end of the choke mandrel and is provided with a seat 69 and a plurality of lateral ports 70 positioned above the seat and below the lower end of the choke mandrel. An elongate valve stern 71 is slidable in the bore of the choke mandrel and has a reduced lower end portion 72 on which is disposed a ring seal 73 between the downwardly facing annular shoulder 74 at the upper end of the reduced portion of the valve stem and a cap sleeve 75 fitted on the lower end of the reduced end portion 72 of the stem. A shear pin 73a extends through registering apertures in the cap 63, the cap sleeve 73 and in the reduced end portion 72 of the valve stem to hold the stern in the position shown in Figure 5. lt will be apparent that the ring seal 73 prevents passage of iluid downwardly to or upwardly from the lateral ports between the valve stem and the choke mandrel.

The choke C may be used for acidizing or similar operations where it is desirable to cause fluid to llow downwardly through the dow string to the annular space exteriorly of the flow string, particularly to such annular space between packers sealing olic between the llorw string and well bore above and below a producing formation. The acidizing fluids would ow through the annular passage 7i between the landing nipple and the housing, up through the bore l of the nipple, through the ports 2l and i6 and 17 to the exterior of the housing. The fluid is prevented from flowing downwardly through the sub l2 by the chevron packing assembly 66 and the ring seal 73. At the same time iiuid may not tlow up from lower sections of the iiow string through the sub 12.

The choke C' may also be used where it is desired to allow only fluid from the exterior of the housing 1t) to ow through the ports i6 and 17 in the housing and the ports 2l in the landing nipple into the bore of the housing, and thence upwardly through the annular passage 74 into the upper sections of the flow string. The chevron packing 66 and the ring seal 73 will prevent any uid from the lower sections of the tlow string from owing into the housing.

lf it is desired to permit commingling of the liuids on the exterior of the housing and liowing upwardly through the sub l2, the choke C may be removed in the same manner as the choke C. A downward blow on the upper end of the valve stem 7 will cause the O-ring 40 to spring out of its groove and will shear the pin 73a at the lower end of the stem. The valve stern 71 will then move downwardly until its downward movement is stopped by the seat 69 in the cap on the lower end of the choke mandrel. Fluid from lower sections of the flow string may now flow through the lateral ports 70 in the cap 68 into the annular space 76 between the valve stem 71 and the choke mandrel, and thence upwardly through ports l77 in the mandrel above the lower anges 64 into the annular passage 74 between the landing nipple and the housing. The pressures acting on the choke C will thus be substantially equalized, and the locking mandrel may be moved downwardly by a blow on the upper end of the tubular neck member to free the dogs 45 for movement into retracted position. The choke C can then be lifted out by a suitable pulling tool which engages the ange 53 of the dog carrier. Fluid from both the exterior of the housing and that flowing upwardly through the sub 12 will now commingle and ow upwardly through the iiow string.

it will be seen that the choke C and the choke C' act with the by-pass tool as separation tools since they close off the side ports 21 or the sub 12 to separate lluids exteriorly of the dow string from those interiorly of the liow string below the by-pass tool. The term choke as used herein includes the anchoring means and packing or sealing means and may include the valve means initially closed and openable to permit liow therepast.

The foregoing description of the invention is explanatory only, and changes in the details of the construction illustrated may be made by those skilled in the art, within the scope of the appended claims, without departing from the spirit of the invention.

What we claim and desire to secure by Letters Patent is:

1. A well tool including, an outer tubular member; an inner tubular member within said outer tubular member and spaced therefrom to form a flow passage therebetween; said inner and outer members each having a lateral port formed therein; means connecting said ports of said inner and outer members to establish a iiow passage from the port of the outer member through the port of the inner member to the interior of said inner member; said inner member having its upper and lower ends communicating with the interior of said outer member; said outer member being connectable in the flow string of a well; said inner member having a cylindrical sealing surface in its bore above and below said lateral opening in said inner member; said outer tubular member having its bore reduced to form a sealing surface therein spaced longitudinally from the inner member.

2. A well tool including, a housing having a longitudinal ow passage therethrough and means providing a choke landing bore, said longitudinal flow passage being disposed exteriorly of the choke landing means, the upper and lower ends of said choke landing means communicating with the flow passage of the housing, a lateral couductor in the housing establishing communication between the exterior of said housing and the base of said choke landing means, said means providing the choke landing bore having cylindrical sealing surfaces therein above and below the lateral conductor, and said housing having its base reduced to provide a cylindrical sealing surface therein below the lower end of the choke landing means.

3. A well tool of the character set forth in claim 2 and including: a removable choke having a bore therein and disposed in said choke landing bore and having sealing means engaging at least one of said sealing surfaces in said landing bore and housing to control flow of iiuids through said housing and said lateral conductor, said choke also having means controlling flow of iiuids through its bore.

4. A well tool comprising: an elongate tubular housing connectable in the ow string of a well, said housing having a lateral port intermediate its ends, and an elongate tubular landing nipple disposed concentrically in lsaid housing and having one of its ends disposed between one of the ends of said housing and said port, said landing nipple being of substantially smaller diameter than said housing whereby an annular passage is formed therebetween, said nipple having an integral lateral wing eX- tending to and abutting said housing, said wing being provided with a lateral bore communicating with said port and with the interior of said landing nipple, said housing having a portion-or" its.b ore spaced longitudinally from said landing nipple reduced to a diameter not greater than the bore or" the landing nipple and axially aligned therewith.

5. A well tool comprising: an elongate tubular housing connectable in the tlow string of a well, said housing having a lateral port, and an elongate tubular landing nipple disposed in said housing and having its lower end disposed between the lower end of said housing and said port, said nipple being of substantialiy'smaller diameterV than said housing whereby a flow passagtherebetween, said nipple having an extension projecting laterally therefrom to said housing and having a bore communicating with said port and the interior of said landing nipple, said housing, having a bore providing a cylindrical sealing surface therein below the lower end of the landing nipple.

6.v A well tool comprising: an elongate tubular housing connectable in the tlow string or" a well, said housingY having a lateral port, and an elongate tubular landing Y nipple disposed in said housing and having its lower end disposed between the lower end of said housing and said port, said nipple being of substantially smaller diameter than said housing whereby a flow passage is formed therebetween, said nipple having an extension projecting laterally therefrom to said housing and having a bore cornmunicating with said port and the interior of said landing nipple, said landingnipple being provided with an annular internal grooveV adjacentrthe upper end thereof for cooperation with locking members of a choke insertable projecting laterally therefrom to said housing and having Va lateral flow'passage therein communicating with said lateral port of the housing and with the interior of said landing nipple, said housing having a sub secured to the lower end thereof, said sub having a bore of a diameter not greater than the diameter of the bore of said landing nipple.

8. A well tool comprising: an elongate tubular housing connectablein the How string of a well, said housing having a lateral port, an elongate tubular landing nipple disposed in said housing and having its'lower end communicating withtherlower end of said housing, said nipple being of substantially smaller diameter than said housing whereby a ow passage is formed therebetween,V said nipple having an extension projecting laterally therefrom to said housing and having a bore therein communicating with the lateral port of the housing and with the interior of said landing nipple, and a removable choke disposed in said landing nipple, said choke including sealing means disposed above and below said extension bore and sealing between saidV choke and said landing nipple, and retractable locking means on its upper end engageable with the landing nipple above the seal to hold the choke in place therein, said housing having a bore providing a cylindrical sealing surface therein below the lower end of the` landing nipple.

9. A well tool comprising: an elongate tubular housing connectable in the flow Vstring of a well, said housing having a lateral port, and an elongate tubular landing nipple disposed concentrically in said housing and having its lower end communicating with the lower end of said housing, said nipple being of substantially smaller diameter than said housing` whereby an annular ow passage is formed therebetween,k said nipple. having an extension projecting laterally' therefromto. said' housing and having a boreV corru'nunicating'rwith said` lateral port` of the. housingrandwith the interior of saidrlanding. nipple, a removable choke4 disposed inV said landingV nipple, said choke v comprising amandrel having a' longitudinal bore openat its upper endiandclosed at its lower end and having a lateral opening intermediate its ends communicating with the exterior of said Vmandrel and with the longitudinal'bore osaid mandrel, a valve member in said longitudinal bore f disposed above' said' lateral opening for sealing saidbore to prevent ow of iluid from below the valvetupwardly through the longitudinal bore of the choke, said valve having a stem projecting upwardly above the upper end of theV choke whereby said valve may be opened by moving said valve stem downwardly, and uid excluding t sealing means -between said choke'and said nipple disposed above and beneath said lateral bore of said landing nipple extension, said lateral opening vof the mandrel-communifeating with said lateral bore' of the nipple extension where-l by liud may pass from the exterior of said housing'into f the longitudinal bore of the mandrel and out of said longitudinal bore of said mandrel when said valve is moved to open-,position whereby fluid pressures above Vand below said choke may be equalized to facilitate removal of said` choke. d

10. A well tool comprising: an elongate tubular housing connectable in the flow string of a Well, said housingVV having a lateral port, an elongate tubular landing nipple disposed concentrically in said housing and havin'g'its lower end communicating with the lower end of said housing, said nipple being of smaller diameter than said hous` ing whereby an annular ow passage is formed therebetween, said nipplevhaving an extension projecting laterally therefrom to said housing and having a lateral bore therein communicating with said housing port and with the interior of said landing nipple, said housing having a Y'tubular extension secured to the lower end thereof, said Vhousing extension having'a bore of a diameter not greater than the diameter of the bore of said landing nipple, and a removable choke extending through said landing nipple and into said tubular housing extension, said choke comprising an elongate mandrel having a longitudinal borek and a lowerr opening adjacent its lower end communicating with the Vbore of the housingrextension and with the interior of said mandrel in saidhousing extension, a

Vvalve member in said longitudinal mandrel bore disposed above said lower opening for preventing ilow of fluid from said lower opening upward through the longitudinal bore of the mandrel, said mandrel also having a lateral `aperture above said valve communicating with said longitudinal mandrel bore and with the annular ow passage between the landing nipple'and housing, sealing means disposed between said mandrel and said landing nipple-above the l. lateral bore of said lateral extension of said landing nip-Y ple, sealing means disposed between said mandrel and said housing extension and on the mandrel betweensaid lateral opening and lower opening in said mandrel, and Y means for'moving said valve member downwardly to permit fluid to flow upwardly from said tubular housing ex-` tension through said lower longitudinal bore of'said mandrel outwardly through the lateral opening of the mandrel into said annular flow passage to equalize fluid `posed in saidhousing and having its lower end spaced from the cylindrical sealing surface at the lower end of said housing; said landing nipplebeing of substantiallyV smaller diameter than said housing whereby a How passage `is formed betweensai'd housing and the vexterior of said llanding-nipple; and'means-providing a lateral passageway communicating with the exterior of the housing and with the interior of the landing nipple.

12. A well tool of the character set forth in claim 1l and means removably mounted in the housing and closing the bore thereof at said cylindrical sealing surface.

13. A well tool of the character set forth in claim l1 and including: valve means removably positioned in said housing closing the sealing surface portion of the bore of said housing at the lower end of the housing, said valve means being initially closed and openable to permit flow therepast.

14. A well tool including: an elongate housing connectable in a well ow conductor and having a longitudinal bore; an elongate landing nipple having a longitudinal ow passage therein, said nipple being mounted in the housing and positioned to provide a ow passage exteriorly thereof between said housing and said landing nipple; and a lateral ilow passageway providing communication at its outer end with the exterior of the housing and at its inner end with the flow passage of said landing nipple, the inner end of said lateral flow passageway being positioned intermediate the ends of the landing nipple, said housing having a portion of its bore wall providing a sealing surface below the lower end of said landing nipple.

15. A well tool of the character set forth in claim 14 and including: means removably positioned in said housing closing the sealing surface portion of the bore of the housing below the lower end of said landing nipple.

16. A well tool comprising: an elongate tubular housing connectable in the ow string of a well, said housing having a lateral port, and an elongate tubular landing nipple disposed concentrically in said housing and having its lower end communicating with the lower end of said housing, said nipple being of substantially smaller diameter than said housing whereby an annular llow passage is formed therebetween, said nipple having an extension projecting laterally therefrom to said housing and having a bore communicating with said lateral port of the housing and with the interior of said landing nipple, a removable choke disposed in said landing nipple, said choke comprising a mandrel having a longitudinal bore open at its upper end and closed at its lower end and having a lateral opening intermediate its ends communicating with the exterior of said mandrel and with the longitudinal bore of said mandrel, a valve member in said longitudinal bore disposed above said lateral opening for sealing said bore to prevent ow of fluid from below the valve upwardly through the longitudinal bore of the choke, a stern projecting upwardly from said valve and exposed at its upper end through the open upper end of the longitudinal bore of the choke whereby it may be opened to permit flow therepast, and fluid excluding sealing means between said choke and said nipple disposed above and beneath said lateral bore of said landing nipple extension, said lateral opening of the mandrel communicating with said lateral bore of the nipple extension whereby uid may pass from the exterior of said housing into the longitudinal bore of the mandrel and out of said longitudinal bore of said mandrel when said valve is moved to open position.

References Cited in the tile of this patent UNITED STATES PATENTS 2,230,107 Garrett Ian. 28, 1941 2,246,811 Otis June 24, 1941 2,255,648 Bryan Sept. 9, 1941 2,571,478 Otis Oct. 16, 1951 2,695,671 Kingston Nov. 30, 1954 

